摘要
原子量是最为基础的科学概念之一,"国际纯粹与应用化学联合会(IUPAC)"之"同位素丰度和原子量委员会(CIAAW)"每两年会修订并发布一次原子量。自2009年起,IUPAC宣布某些元素的原子量不再是常数,这些元素的标准原子量为区间值。为方便使用,对于这些元素,给出一个合理的单一数值,称为常规原子量。何为标准原子量?何为常规原子量?为何某些元素的原子量出现区间值?依据原子量数值的特性,元素可以分为几大类?本文在介绍最新元素周期表中原子量的特点之后,简述原子量测定、标准确定、概念演变的发展历史,讨论原子量的修订与变化等问题。
Atomic weight is one of the fundamental scientific concepts. "The IUPAC Commission on the Isotopic Abundances and Atomic Weights" revises and releases atomic weights of the elements every two years. Since 2009, IUPAC announced that the atomic weights of some elements are no longer constants of nature, and the standard atomic weights of these elements span an interval. For the convenience of users, a single value is also provided for these elements, which is called "conventional atomic weight". What is the standard atomic weight? What is a conventional atomic weight? Why do the atomic weights of some elements span an interval? According to the characteristics of atomic weight values, how many classes can the elements be divided into? After introducing the characteristics of atomic weights in the latest periodic table of the elements, this article briefly deals with the history of atomic weight determination, the development of the standard of the unified atomic mass unit, and then discusses the revision and changes of atomic weights.
作者
王颖霞
周公度
WANG Yingxia;ZHOU Gongdu(College of Chemistry and Molecular Engineering,Peking University,Beijing 100871,P.R.China)
出处
《大学化学》
CAS
2019年第12期22-28,共7页
University Chemistry
关键词
原子量
标准原子量
常规原子量
同位素丰度
原子量区间
原子质量单位
Atomic weight
Standard atomic weight
Conventional atomic weight
Isotope abundance
Atomic weight interval
Atomic mass unit
